Flame retardant plastics compositions based on a polyamide, a polyolefin, and magnesium hydroxide reinforced with 3-30 wt. % of glass fibres are known from EP-A-335 165. It should be noted that the presence of glass fibres is essential to sufficiently flame retardant properties being obtained. The drawbacks to compositions containing glass fibres are that their preparation results in heavy wear on the extruders while the products formed from them give rise to warping.
A further drawback to the known compositions is that they cannot easily be injection moulded because of a high apparent melt viscosity at the ensuing rates of shear.